Add illustration of Admonition types (#836)

Co-authored-by: Eric Arellano <[email protected]>

README.md

@@ -441,7 +441,8 @@ To use an `Admonition`, use the following syntax
 <Admonition type="note">This is a __note__ example</Admonition>
 ```
 
-Available types are `note, tip, info, caution, danger`
+Available types are `note, tip, info, caution, danger`. This is what they look like:
+![types](https://github.com/Qiskit/documentation/assets/66339736/ebf5794e-45eb-49ee-97df-41ff08ee876d)
 
 By default, the title is the `type` capitalized. You can customize it by setting `title`: